[QuinnSjoblom]

trying my hand at folding knives. the titanium scales went excellent, parts are perfect. eventually will do blades from cpm 154 but i thought i would try some cheaper 1095 first. my blade stock is 5/32 thick by 2 inches wide and has just a very slight cup across the 2 inches and pretty straight lengthwise. blades will finish at 1/8 thick so about 15 thou to come off each face to flatten. i am doing this on the mill, no surface grinder. I placed a piece of blade stock in my 6 inch vise on tall enough parallels to leave about 30 thou above jaws to face off. I intentionally did not push any bow or twist out of the stock when placing in jaws so that it actually removes the error when facing. i also made sure there was no significant deflection while tightening the vise. i expected to end up with a fairly flat surface after facing but it didnt go so well. i faced off about 15 thou and when releasing the jaws, it curled like a potato chip, far worse than the stock was originally. is there really that much stress right in the skin of the stock? why is it curling so bad? the 1095 bars are advertised as annealed, but should i be stress relieving it before machining? i really did not expect much movement from taking 15 thou off one face. any tips?

[mactec54]

trying my hand at folding knives. the titanium scales went excellent, parts are perfect. eventually will do blades from cpm 154 but i thought i would try some cheaper 1095 first. my blade stock is 5/32 thick by 2 inches wide and has just a very slight cup across the 2 inches and pretty straight lengthwise. blades will finish at 1/8 thick so about 15 thou to come off each face to flatten. i am doing this on the mill, no surface grinder. I placed a piece of blade stock in my 6 inch vise on tall enough parallels to leave about 30 thou above jaws to face off. I intentionally did not push any bow or twist out of the stock when placing in jaws so that it actually removes the error when facing. i also made sure there was no significant deflection while tightening the vise. i expected to end up with a fairly flat surface after facing but it didnt go so well. i faced off about 15 thou and when releasing the jaws, it curled like a potato chip, far worse than the stock was originally. is there really that much stress right in the skin of the stock? why is it curling so bad? the 1095 bars are advertised as annealed, but should i be stress relieving it before machining? i really did not expect much movement from taking 15 thou off one face. any tips?

Any material, thin flat stock like this, the skin tension can be high, stress relieving will help, if it gets done at the right temperature, annealing is done at a different temperature, so the stress is still in the part.

Some Titanium parts I used to machine had to be stress relieved between machining operations, normally twice for each part.

[QuinnSjoblom]

Any material, thin flat stock like this, the skin tension can be high, stress relieving will help, if it gets done at the right temperature, annealing is done at a different temperature, so the stress is still in the part.

Some Titanium parts I used to machine had to be stress relieved between machining operations, normally twice for each part.

sounds good. I did have better luck on the second attempt after removing both surface skins. Im currently building a heat treat oven for hardening my blades so i will add stress relieving to the process since ill have that ability.